Electric air cleaner composed of non-thermal plasma reactor and electrostatic precipitator

Recent concerns of environmental protection encourage the use of a compact indoor air cleaner and various types of electrostatic precipitators (ESPs). Although a wide range of particles in the air, such as airborne dusts, can be collected effectively with an ordinary ESP using a DC corona discharge, it is difficult to remove gaseous compounds such as tobacco smoke which induce submicron particles and an offensive odor. In the present study, the authors investigated the collection of submicron particles and the decomposition of acetaldehyde (CH₃CBO) using a commercial ESP and a nonthermal plasma reactor because the offensive odor of tobacco smoke is mainly caused by acetaldehyde molecules. For the ESP, they evaluated particle-size dependent collection efficiency using a monodispersed aerosol because little investigation has been conducted in this area. As for the decomposition of acetaldehyde, more than 90% decomposition efficiency was obtained with the use of nonthermal plasma under dry air. However, the decomposition deteriorated under humidified conditions. A higher collection efficiency was achieved for a particle size of 0.6 μm than that of 0.3 μm, although the overall collection efficiency exceeded 99%. The combination of the two technologies leads to a breakthrough in conventional indoor electronic air cleaner technology